Hello,
There are many skins which are to use by ovidentia,
i cant answer you if i cant see it,
can you show me your site ?
Which is the menu which has the issue ?

the css for user's menu is ovidentia.css there are 3 class
.bab_section bab_usersection
.bab_section bab_usersection>.bab_title
.bab_section bab_usersection>.bab_content
your problem must be than the background-color propriety of
" .bab_section bab_usersection " isnt the same than " .bab_section bab_usersection>.bab_content "